Conventionally, a semiconductor device 200 using a lead frame is proposed, as illustrated in FIG. 8. In this semiconductor device 200, the side on the lead frame 210 on which the semiconductor element is mounted and the regions between the lead terminals 211 are molded in resin 219. Each lead terminal 211 is connected to the semiconductor element 218 on the semiconductor element mounting section 216 by means of bonding wires 217. Furthermore, an exposed portion of each lead terminal 211, which is exposed from the resin 219, is plated in such a manner that solder can be jointed readily to same.